I'm planning to go for the software only tune on my 135i (likely a reflash via cobb or evolve-R, no piggy backs). I'm not willing to add any other bolt ons such as exhausts/DP's, and I don't want to add an intercooler either so the car will look 100% stock.

My question is are there certain things I can do to improve the odds of the car running stable after the tune, given that I'll be using a non-aggressive map? I absolutely hate the idea of engine errors/overheating/limp modes/HPFP failures etc.

The car currently has about 20k miles on it. I read it somewhere that it's recommended to replace spark plugs at this stage to make the tune work better. I'll likely also change the air filter (OEM, or is a drop-in worth it?). Will do an oil change too.

Well Intercooler would be great idea going more boost to avoid heatsoak. And if u have n54 good to delete mid cats with stock n55 mid section to let turbo breath easier... Good luck

+1. Two very good ideas.

With such low miles on your car... I'd say you could wait on spark plugs. But new ones could not hurt. I only have a SW flash tune... and I LOVE IT! The engine drives 100% like stock... except I have another 80HP or so. Throttle respose is great and what I noticed most was teh power does drop off a cliff after 5,500 rpms like stock. Now the engine still makes power until 6,300 rpms or so. I hardly every rev that high anyway. Also my top speed has gone way up! Before I was liited to 250 kph(it was really 240 with GPS) now I have seen 280 kph. No engine check lights, no hesitation, no stalling, nothing. The engine just plain runs perfect - abiet with more power. Much more.

Maybe just make sure all your injectors and coil packs are up to date(any recalls?) and the HPFP is working fine. Other than that you are good to go!

I just changed my air filter with another OEM one. There wa slots of sand and small rocks in that airbox! I would hate to think what would happen with some "other" filters in there. Maybe change the oil & filter. Once you flash you will need new tires... bc traction will become an issue.

Make sure your recalls are all up to par,then I would change the oil,Plugs,air filter,delete the rear cats,and then reflash and enjoy..I'll give your 3 months and your going to want d.ps ,this is the bread and butter of it.I would consider the giac flash ,it's very good and consistent ..

The car is a 2010 N54, from what I understand it has all the updated HPFP and injectors/coils already? Or should I call up the dealer and make them do a VIN check.

DP is definitely a no go for me... I don't want to deal with all the lights/emission checks and the hassle of installing/uninstalling for any service. As far as the exhaust goes, I did a search and it seems people suggest that the gain really isn't significant? Will deleting the mid or rear cats cause engine light/emission related issues and do I have to reinstall for dealer service as well?

Also is FMIC really that important? I usually don't drive very aggressively at all and I just want some extra power in the rare "spirited situations" and better throttle feeling. Is overheating a major concern with bone stock + flash?

Yes the intercooler in the n motors are a weak link..if you did 2 back
To back pulls,the car would loose a good bit of power due to heatsoaking!I was on the same boat as you with the downpipes,but after just the flash and dci the power wasn't enough .As long as you have good software ,there will be in issue with any lights or issues..

The car is a 2010 N54, from what I understand it has all the updated HPFP and injectors/coils already? Or should I call up the dealer and make them do a VIN check.

DP is definitely a no go for me... I don't want to deal with all the lights/emission checks and the hassle of installing/uninstalling for any service. As far as the exhaust goes, I did a search and it seems people suggest that the gain really isn't significant? Will deleting the mid or rear cats cause engine light/emission related issues and do I have to reinstall for dealer service as well?

Also is FMIC really that important? I usually don't drive very aggressively at all and I just want some extra power in the rare "spirited situations" and better throttle feeling. Is overheating a major concern with bone stock + flash?

I would have a dealer sheck your VIN and see if any recalls are open. Maybe even as IF there are any "service actions" (not a recall per se) that you should be aware of. Like the tail light LEDs failing or third brake light, ect.

Deleting the secondary cats(ie using a N55 mid pipe) will not cause an engine check light. There are only O2 sensors before and after the main cats (downpipes).

An exhaust will only change the sound. No real gains. Some had said 5hp. Thats really nothing on a 300 to 400 Hp car.

Dackel

PS: speaking of mods... one of teh best mods I have done is the CDV delete. Don't know IF you have a 6MT or 6AT. ? Also the Performance SSK is really sweet. Thumbs way up on both mods. Lots of people wear the performance Exhaust was their best mod. Sometimes I wish my car had one.

Does "deleting the cats" require any aftermarket parts? (I mean if u just remove them, won't that make the total length of exhaust short) Can it be done at any muffler shop? Can I take the car in for service as is and will it pass emission test?

Sorry I'm kind of new at this. It'd be great if someone can explain to me how it works (which cats to delete and what happens after the delete etc)

These things won't really improve power (much), however it will keep you out of limp mode if you are really exploiting the extra power the tune will give you.

I run stock, but some have said that the diverter valves leak when you start making larger amounts of boost. If this is true, then you may want to upgrade your diverter valves.....Again, won't look stock though.

If you subscribe to the theory that the stock n54 intake is junk, then you could use a drop-in filter for a few extra cfm, or replace it altogether (but loose your stock look)

Does "deleting the cats" require any aftermarket parts? (I mean if u just remove them, won't that make the total length of exhaust short) Can it be done at any muffler shop? Can I take the car in for service as is and will it pass emission test?

Sorry I'm kind of new at this. It'd be great if someone can explain to me how it works (which cats to delete and what happens after the delete etc)

Thanks!

It will not afect your emission maybe a little but u still can pass inspection w/o any probs because N55 don't have them on stock exhaust. Would be best way to delete them by putting N55 mid exhaust section on your car and it will look and work 100% OEM. Downpipes different story, I would leave them stock.

I'd take the car in for one last service before making any chances, just so you can get whatever's needed under warranty. I'm not 100% sure if a software tune will void warranty but it's better to be safe than sorry. HPFP would be the most worrying. I got "Engine Fault. Power Reduced" the day before I was planning to load my Evolve tune. Took it to a dealer and they sorted it out. Supposedly it was low on oil but I wasn't getting a message.

I'm not too sure how the COBB tune works but with the Evolve tune, you pull down your OEM tune data, Evolve modify it and then you load the revised file up. You will always want to retain your OEM tune file so I guess in case of failure, you can load the OEM file before taking it to the dealership.

I'd take the car in for one last service before making any chances, just so you can get whatever's needed under warranty. I'm not 100% sure if a software tune will void warranty but it's better to be safe than sorry. HPFP would be the most worrying. I got "Engine Fault. Power Reduced" the day before I was planning to load my Evolve tune. Took it to a dealer and they sorted it out. Supposedly it was low on oil but I wasn't getting a message.

I'm not too sure how the COBB tune works but with the Evolve tune, you pull down your OEM tune data, Evolve modify it and then you load the revised file up. You will always want to retain your OEM tune file so I guess in case of failure, you can load the OEM file before taking it to the dealership.

Thanks a lot for the heads up. How do you like your Evolve tune? I'm planning to go Evolve too because I like the loyalty program where you only pay a small fee when you change to another vehicle.

Do you have any other mods other than the tune? I'm planning to leave the car mostly stock besides the tune. I might do the CDV delete and a N55 mid pipe swap though.

I'm planning to go for the software only tune on my 135i (likely a reflash via cobb or evolve-R, no piggy backs). I'm not willing to add any other bolt ons such as exhausts/DP's, and I don't want to add an intercooler either so the car will look 100% stock.

My question is are there certain things I can do to improve the odds of the car running stable after the tune, given that I'll be using a non-aggressive map? I absolutely hate the idea of engine errors/overheating/limp modes/HPFP failures etc.

The car currently has about 20k miles on it. I read it somewhere that it's recommended to replace spark plugs at this stage to make the tune work better. I'll likely also change the air filter (OEM, or is a drop-in worth it?). Will do an oil change too.

What else would you recommend?

I had some of the same concerns...here is what I recommend based on my research:

I did not change my down pipes or mid pipes due to potential error codes but mainly emissions. I did not get a definitive answer regarding the IL State Emissions. That said, sounds like the N55 has no cats in the mid pipe (?) So, maybe Berk resonated mid pipes in the future but I did change to Berk Street Performance axle back.

Air filter ...just used the existing box and purchased an aFe drop in filter. This will start a debate but from what I read and heard there is no need to mod the air filter since the hP gain is minimal if anything at all.

I did consider upgrading or adding another oil cooler but I'm not going to track the car so to my understanding I can skip this mod.

Hi, what does the delete of cats on a N54 with replacment with the N55 mid pipes do for performance, i.e horse power and throttle response? Will it be picked up by BMW or can we still maintain our warranties? I also heard that this mod produces a bad smell, is this true. What does it do for the sound, I have the bmw perf exh. I really would like to do this conversion if it works and looks the same as oem.

Hi, what does the delete of cats on a N54 with replacment with the N55 mid pipes do for performance, i.e horse power and throttle response? Will it be picked up by BMW or can we still maintain our warranties?

??? delete of cats would increase flow and hp. BMW and warranty is another reason I did not change the down or mid pipes.